My dad injured his shoulder about a month ago.?

It turns out that he has a major rotator cuff tear that is limiting his arm movement substantially. The orthopedic doctor told him that surgery might not be an option if the tendons, tissues in his shoulder were too worn down. He is 63 and very active, loves to golf, and I am worried he will not be able to be as active if repairs are not made surgically. Please respond if you have heard of or experienced similar problems or have advice. Are there alternatives to reaching a reasonable recovery?